High temperature molded dielectric bead for coaxial connector

Abstract

A dielectric support bead for a coaxial connector is provided. The support bead comprises a center support portion and a plurality of spaced apart outer support surfaces disposed concentrically about the inner support portion. The inner support portion includes a central through aperture dimensioned to be pressfit over the center conductor of a coaxial connector. The outer supports define segments of a cylinder and are dimensioned for pressfit engagement with the outer conductor of the coaxial connector. The outer support surfaces are maintained in concentric relationship to the center support portion by a plurality of support legs. Concave generally cylindrical surfaces extend continuously between adjacent support legs and are generated about axes extending parallel to and disposed symmetrically about the central axis of the bead. An annular shroud is disposed adjacent one end of the bead to prevent contaminants from entering the body of the connector.

We claim: 
     
       1. A dielectric support bead for maintaining a center conductor of a coaxial connector in spaced coaxial relationship to an outer conductor thereof, said support bead comprising a center support portion having a central through aperture extending axially therethrough, said central through aperture being dimensioned for pressfit engagement with the center conductor of the coaxial connector, a plurality of spaced apart outer support surfaces defining segments of a cylinder, said outer support surfaces having an external diameter for engagement with the outer conductor of the coaxial connector, said outer support sur-aces being maintained in spaced relationship to said inner support portion by support legs extending generally radially therebetween, a substantially annular shroud disposed around said inner support portion and defining an outer circumference having a radius substantially equal to the radius defined by said outer support surfaces, said shroud being operative to prevent contaminants from entering the coaxial connector at locations intermediate said support legs. 
     
     
       2. A dielectric support bead as in claim 1, wherein said dielectric support bead comprises opposed longitudinal ends, said shroud being disposed in proximity to one said longitudinal end of said dielectric support bead. 
     
     
       3. A dielectric support bead as in claim 1 wherein portions of said support bead intermediate adjacent support legs thereof are defined by generally continuous arcuate concave surfaces. 
     
     
       4. A dielectric support bead as in claim 3 wherein said concave arcuate surfaces define generally cylindrical surfaces having respective axes aligned substantially parallel to the axis of said central through aperture in said support bead. 
     
     
       5. A dielectric support bead as in claim 4 wherein the axes of the concave generally cylindrical surfaces between adjacent support legs are disposed at equal distances from the longitudinal axis of said support bead. 
     
     
       6. A dielectric support bead as in claim 5 wherein the distance between the longitudinal axis of said dielectric support bead and the axes of said concave generally cylindrical surfaces exceeds the radius defined by the outer support surfaces. 
     
     
       7. A dielectric support bead as in claim 1 further comprising generally annular undercuts adjacent the opposed longitudinal ends of said dielectric support bead. 
     
     
       8. A dielectric support bead as in claim 1, wherein said bead is unitarily molded from a plastic material. 
     
     
       9. A dielectric support bead as in claim 8 wherein the plastic material is ULTEM. 
     
     
       10. A high frequency coaxial connector for use in high temperature environments, said connector having a mating end for connection to a mating connector, and having an opposed end, said connector comprising: a center conductor one end of which is free and generally disposed at the mating end of said connector for engagement with said mating connector;   an outer conductor spaced from said center conductor and disposed centrally thereabout; and   an injection molded dielectric support bead formed from a plastic material, said support bead comprising a center support portion having a central through aperture extending axially therethrough, said central through aperture being pressfit over the center conductor of the coaxial connector, a plurality of spaced apart outer support surfaces defining segments of a cylinder, said outer support surfaces being radially disposed relative to the center support portion to be in engagement with the outer conductor of the coaxial connector, said outer support surfaces being maintained in spaced relationship to said inner support portion by respective support legs extending generally radially between the inner support portion and the associated outer support surface, a substantially annular shroud disposed around said inner support portion and defining an outer circumference having a radius substantially equal to the radius defined by said outer support surfaces, said shroud being operative to prevent contaminants from entering the coaxial connector at locations intermediate said support legs.   
     
     
       11. A coaxial connector as in claim 10 wherein said dielectric support bead comprises opposed longitudinal ends, said shroud being disposed in proximity to one said longitudinal end of said dielectric support bead. 
     
     
       12. A coaxial connector as in claim 10 wherein portions of said support bead intermediate adjacent support legs thereof are defined by generally continuous arcuate concave surfaces. 
     
     
       13. A coaxial connector as in claim 12 wherein said concave arcuate surfaces define generally cylindrical surfaces having respective axes aligned substantially parallel to the axis of the central through aperture in said support bead. 
     
     
       14. A coaxial connector as in claim 13 wherein the axes of the concave generally cylindrical surfaces between adjacent support legs are disposed at substantially equal distances from the longitudinal axis of said support bead. 
     
     
       15. A coaxial connector as in claim 14 wherein the distance between the longitudinal axis of said dielectric support bead and the axes of said concave generally cylindrical surfaces exceeds the radius defined by the outer support surfaces of the dielectric support bead. 
     
     
       16. A coaxial connector as in claim 10 wherein the dielectric support bead further comprises generally annular undercuts adjacent the opposed longitudinal ends thereof. 
     
     
       17. A coaxial connector as in claim 10 wherein the dielectric support bead is molded from ULTEM plastic.